isci: unify remote_device start_task_handlers

Implement all states in scic_sds_remote_device_start_task() and delete
the state handler.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

2 files changed, 90 insertions, 152 deletions

diff --git a/drivers/scsi/isci/remote_device.c b/drivers/scsi/isci/remote_device.c
index 3580c0a5a719..3e7e95200a1e 100644
--- a/drivers/scsi/isci/remote_device.c
+++ b/drivers/scsi/isci/remote_device.c
@@ -521,22 +521,97 @@ enum sci_status scic_sds_remote_device_complete_io(struct scic_sds_controller *s
         return status;
 }
 
-/**
- *
- * @controller: The controller that is starting the task request.
- * @sci_dev: The remote device for which the start task handling is being
- *    requested.
- * @io_request: The task request that is being started.
- *
- * This method invokes the remote device start task handler. enum sci_status
- */
-enum sci_status scic_sds_remote_device_start_task(
-        struct scic_sds_controller *controller,
-        struct scic_sds_remote_device *sci_dev,
-        struct scic_sds_request *io_request)
+static void scic_sds_remote_device_continue_request(void *dev)
+{
+        struct scic_sds_remote_device *sci_dev = dev;
+
+        /* we need to check if this request is still valid to continue. */
+        if (sci_dev->working_request)
+                scic_controller_continue_io(sci_dev->working_request);
+}
+
+enum sci_status scic_sds_remote_device_start_task(struct scic_sds_controller *scic,
+                                                  struct scic_sds_remote_device *sci_dev,
+                                                  struct scic_sds_request *sci_req)
 {
-        return sci_dev->state_handlers->start_task_handler(
-                       sci_dev, io_request);
+        struct sci_base_state_machine *sm = &sci_dev->state_machine;
+        enum scic_sds_remote_device_states state = sm->current_state_id;
+        struct scic_sds_port *sci_port = sci_dev->owning_port;
+        enum sci_status status;
+
+        switch (state) {
+        case SCI_BASE_REMOTE_DEVICE_STATE_INITIAL:
+        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPED:
+        case SCI_BASE_REMOTE_DEVICE_STATE_STARTING:
+        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
+        case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
+        case SCI_BASE_REMOTE_DEVICE_STATE_STOPPING:
+        case SCI_BASE_REMOTE_DEVICE_STATE_FAILED:
+        case SCI_BASE_REMOTE_DEVICE_STATE_RESETTING:
+        case SCI_BASE_REMOTE_DEVICE_STATE_FINAL:
+        default:
+                dev_warn(scirdev_to_dev(sci_dev), "%s: in wrong state: %d\n",
+                         __func__, state);
+                return SCI_FAILURE_INVALID_STATE;
+        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:
+        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD:
+        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ:
+        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR:
+        case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_AWAIT_RESET:
+                status = scic_sds_port_start_io(sci_port, sci_dev, sci_req);
+                if (status != SCI_SUCCESS)
+                        return status;
+
+                status = scic_sds_remote_node_context_start_task(&sci_dev->rnc, sci_req);
+                if (status != SCI_SUCCESS)
+                        goto out;
+
+                status = sci_req->state_handlers->start_handler(sci_req);
+                if (status != SCI_SUCCESS)
+                        goto out;
+
+                /* Note: If the remote device state is not IDLE this will
+                 * replace the request that probably resulted in the task
+                 * management request.
+                 */
+                sci_dev->working_request = sci_req;
+                sci_base_state_machine_change_state(sm, SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD);
+
+                /* The remote node context must cleanup the TCi to NCQ mapping
+                 * table.  The only way to do this correctly is to either write
+                 * to the TLCR register or to invalidate and repost the RNC. In
+                 * either case the remote node context state machine will take
+                 * the correct action when the remote node context is suspended
+                 * and later resumed.
+                 */
+                scic_sds_remote_node_context_suspend(&sci_dev->rnc,
+                                SCI_SOFTWARE_SUSPENSION, NULL, NULL);
+                scic_sds_remote_node_context_resume(&sci_dev->rnc,
+                                scic_sds_remote_device_continue_request,
+                                                    sci_dev);
+
+        out:
+                scic_sds_remote_device_start_request(sci_dev, sci_req, status);
+                /* We need to let the controller start request handler know that
+                 * it can't post TC yet. We will provide a callback function to
+                 * post TC when RNC gets resumed.
+                 */
+                return SCI_FAILURE_RESET_DEVICE_PARTIAL_SUCCESS;
+        case SCI_BASE_REMOTE_DEVICE_STATE_READY:
+                status = scic_sds_port_start_io(sci_port, sci_dev, sci_req);
+                if (status != SCI_SUCCESS)
+                        return status;
+
+                status = scic_sds_remote_node_context_start_task(&sci_dev->rnc, sci_req);
+                if (status != SCI_SUCCESS)
+                        break;
+
+                status = scic_sds_request_start(sci_req);
+                break;
+        }
+        scic_sds_remote_device_start_request(sci_dev, sci_req, status);
+
+        return status;
 }
 
 /**
@@ -589,23 +664,6 @@ static void remote_device_resume_done(void *_dev)
         }
 }
 
-/**
- *
- * @request: This parameter specifies the request being continued.
- *
- * This method will continue to post tc for a STP request. This method usually
- * serves as a callback when RNC gets resumed during a task management
- * sequence. none
- */
-static void scic_sds_remote_device_continue_request(void *dev)
-{
-        struct scic_sds_remote_device *sci_dev = dev;
-
-        /* we need to check if this request is still valid to continue. */
-        if (sci_dev->working_request)
-                scic_controller_continue_io(sci_dev->working_request);
-}
-
 static enum sci_status
 default_device_handler(struct scic_sds_remote_device *sci_dev,
                        const char *func)
@@ -737,13 +795,6 @@ static enum sci_status scic_sds_remote_device_default_frame_handler(
         return SCI_FAILURE_INVALID_STATE;
 }
 
-static enum sci_status scic_sds_remote_device_default_start_request_handler(
-        struct scic_sds_remote_device *sci_dev,
-        struct scic_sds_request *request)
-{
-        return default_device_handler(sci_dev, __func__);
-}
-
 static enum sci_status scic_sds_remote_device_default_complete_request_handler(
         struct scic_sds_remote_device *sci_dev,
         struct scic_sds_request *request)
@@ -817,36 +868,6 @@ static enum sci_status scic_sds_remote_device_general_event_handler(
 }
 
 /*
- * This method will attempt to start a task request for this device object. The
- * remote device object will issue the start request for the task and if
- * successful it will start the request for the port object then increment its
- * own requet count. enum sci_status SCI_SUCCESS if the task request is started for
- * this device object. SCI_FAILURE_INSUFFICIENT_RESOURCES if the io request
- * object could not get the resources to start.
- */
-static enum sci_status scic_sds_remote_device_ready_state_start_task_handler(
-        struct scic_sds_remote_device *sci_dev,
-        struct scic_sds_request *request)
-{
-        enum sci_status result;
-
-        /* See if the port is in a state where we can start the IO request */
-        result = scic_sds_port_start_io(
-                scic_sds_remote_device_get_port(sci_dev), sci_dev, request);
-
-        if (result == SCI_SUCCESS) {
-                result = scic_sds_remote_node_context_start_task(&sci_dev->rnc,
-                                                                 request);
-                if (result == SCI_SUCCESS)
-                        result = scic_sds_request_start(request);
-
-                scic_sds_remote_device_start_request(sci_dev, request, result);
-        }
-
-        return result;
-}
-
-/*
  * This method will complete the request for the remote device object.  The
  * method will call the completion handler for the request object and if
  * successful it will complete the request on the port object then decrement
@@ -976,68 +997,6 @@ static enum sci_status scic_sds_stp_remote_device_complete_request(struct scic_s
         return status;
 }
 
-/* scic_sds_stp_remote_device_ready_substate_start_request_handler - start stp
- * @device: The target device a task management request towards to.
- * @request: The task request.
- *
- * This is the READY NCQ substate handler to start task management request. In
- * this routine, we suspend and resume the RNC.  enum sci_status Always return
- * SCI_FAILURE_RESET_DEVICE_PARTIAL_SUCCESS status to let
- * controller_start_task_handler know that the controller can't post TC for
- * task request yet, instead, when RNC gets resumed, a controller_continue_task
- * callback will be called.
- */
-static enum sci_status scic_sds_stp_remote_device_ready_substate_start_request_handler(
-        struct scic_sds_remote_device *device,
-        struct scic_sds_request *request)
-{
-        enum sci_status status;
-
-        /* Will the port allow the io request to start? */
-        status = device->owning_port->state_handlers->start_io_handler(
-                device->owning_port, device, request);
-        if (status != SCI_SUCCESS)
-                return status;
-
-        status = scic_sds_remote_node_context_start_task(&device->rnc, request);
-        if (status != SCI_SUCCESS)
-                goto out;
-
-        status = request->state_handlers->start_handler(request);
-        if (status != SCI_SUCCESS)
-                goto out;
-
-        /*
-         * Note: If the remote device state is not IDLE this will replace
-         * the request that probably resulted in the task management request.
-         */
-        device->working_request = request;
-        sci_base_state_machine_change_state(&device->state_machine,
-                        SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD);
-
-        /*
-         * The remote node context must cleanup the TCi to NCQ mapping table.
-         * The only way to do this correctly is to either write to the TLCR
-         * register or to invalidate and repost the RNC. In either case the
-         * remote node context state machine will take the correct action when
-         * the remote node context is suspended and later resumed.
-         */
-        scic_sds_remote_node_context_suspend(&device->rnc,
-                        SCI_SOFTWARE_SUSPENSION, NULL, NULL);
-        scic_sds_remote_node_context_resume(&device->rnc,
-                        scic_sds_remote_device_continue_request,
-                        device);
-
-out:
-        scic_sds_remote_device_start_request(device, request, status);
-        /*
-         * We need to let the controller start request handler know that it can't
-         * post TC yet. We will provide a callback function to post TC when RNC gets
-         * resumed.
-         */
-        return SCI_FAILURE_RESET_DEVICE_PARTIAL_SUCCESS;
-}
-
 static enum sci_status scic_sds_stp_remote_device_ready_idle_substate_event_handler(
         struct scic_sds_remote_device *sci_dev,
         u32 event_code)
@@ -1154,7 +1113,6 @@ static enum sci_status scic_sds_smp_remote_device_ready_cmd_substate_frame_handl
 
 static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_state_handler_table[] = {
         [SCI_BASE_REMOTE_DEVICE_STATE_INITIAL] = {
-                .start_task_handler     = scic_sds_remote_device_default_start_request_handler,
                 .complete_task_handler  = scic_sds_remote_device_default_complete_request_handler,
                 .suspend_handler        = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler         = scic_sds_remote_device_default_resume_handler,
@@ -1162,7 +1120,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler          = scic_sds_remote_device_default_frame_handler
         },
         [SCI_BASE_REMOTE_DEVICE_STATE_STOPPED] = {
-                .start_task_handler     = scic_sds_remote_device_default_start_request_handler,
                 .complete_task_handler  = scic_sds_remote_device_default_complete_request_handler,
                 .suspend_handler        = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler         = scic_sds_remote_device_default_resume_handler,
@@ -1170,7 +1127,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler          = scic_sds_remote_device_default_frame_handler
         },
         [SCI_BASE_REMOTE_DEVICE_STATE_STARTING] = {
-                .start_task_handler     = scic_sds_remote_device_default_start_request_handler,
                 .complete_task_handler  = scic_sds_remote_device_default_complete_request_handler,
                 .suspend_handler        = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler         = scic_sds_remote_device_default_resume_handler,
@@ -1178,7 +1134,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler          = scic_sds_remote_device_default_frame_handler
         },
         [SCI_BASE_REMOTE_DEVICE_STATE_READY] = {
-                .start_task_handler     = scic_sds_remote_device_ready_state_start_task_handler,
                 .complete_task_handler  = scic_sds_remote_device_ready_state_complete_request_handler,
                 .suspend_handler        = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler         = scic_sds_remote_device_default_resume_handler,
@@ -1186,7 +1141,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler          = scic_sds_remote_device_general_frame_handler,
         },
         [SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE] = {
-                .start_task_handler     = scic_sds_stp_remote_device_ready_substate_start_request_handler,
                 .complete_task_handler  = scic_sds_remote_device_default_complete_request_handler,
                 .suspend_handler                = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler                 = scic_sds_remote_device_default_resume_handler,
@@ -1194,7 +1148,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler                  = scic_sds_remote_device_default_frame_handler
         },
         [SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD] = {
-                .start_task_handler     = scic_sds_stp_remote_device_ready_substate_start_request_handler,
                 .complete_task_handler  = scic_sds_stp_remote_device_complete_request,
                 .suspend_handler                = scic_sds_stp_remote_device_ready_cmd_substate_suspend_handler,
                 .resume_handler                 = scic_sds_remote_device_default_resume_handler,
@@ -1202,7 +1155,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler                  = scic_sds_stp_remote_device_ready_cmd_substate_frame_handler
         },
         [SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ] = {
-                .start_task_handler     = scic_sds_stp_remote_device_ready_substate_start_request_handler,
                 .complete_task_handler  = scic_sds_stp_remote_device_complete_request,
                 .suspend_handler                = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler                 = scic_sds_remote_device_default_resume_handler,
@@ -1210,7 +1162,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler                  = scic_sds_stp_remote_device_ready_ncq_substate_frame_handler
         },
         [SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR] = {
-                .start_task_handler     = scic_sds_stp_remote_device_ready_substate_start_request_handler,
                 .complete_task_handler  = scic_sds_stp_remote_device_complete_request,
                 .suspend_handler                = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler                 = scic_sds_remote_device_default_resume_handler,
@@ -1218,7 +1169,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler                  = scic_sds_remote_device_general_frame_handler
         },
         [SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_AWAIT_RESET] = {
-                .start_task_handler     = scic_sds_stp_remote_device_ready_substate_start_request_handler,
                 .complete_task_handler  = scic_sds_stp_remote_device_complete_request,
                 .suspend_handler                = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler                 = scic_sds_remote_device_default_resume_handler,
@@ -1226,7 +1176,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler                  = scic_sds_remote_device_general_frame_handler
         },
         [SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE] = {
-                .start_task_handler     = scic_sds_remote_device_default_start_request_handler,
                 .complete_task_handler  = scic_sds_remote_device_default_complete_request_handler,
                 .suspend_handler        = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler         = scic_sds_remote_device_default_resume_handler,
@@ -1234,7 +1183,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler          = scic_sds_remote_device_default_frame_handler
         },
         [SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD] = {
-                .start_task_handler     = scic_sds_remote_device_default_start_request_handler,
                 .complete_task_handler  = scic_sds_remote_device_default_complete_request_handler,
                 .suspend_handler        = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler         = scic_sds_remote_device_default_resume_handler,
@@ -1242,7 +1190,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler          = scic_sds_smp_remote_device_ready_cmd_substate_frame_handler
         },
         [SCI_BASE_REMOTE_DEVICE_STATE_STOPPING] = {
-                .start_task_handler     = scic_sds_remote_device_default_start_request_handler,
                 .complete_task_handler  = scic_sds_remote_device_stopping_state_complete_request_handler,
                 .suspend_handler        = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler         = scic_sds_remote_device_default_resume_handler,
@@ -1250,7 +1197,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler          = scic_sds_remote_device_general_frame_handler
         },
         [SCI_BASE_REMOTE_DEVICE_STATE_FAILED] = {
-                .start_task_handler     = scic_sds_remote_device_default_start_request_handler,
                 .complete_task_handler  = scic_sds_remote_device_default_complete_request_handler,
                 .suspend_handler        = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler         = scic_sds_remote_device_default_resume_handler,
@@ -1258,7 +1204,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler          = scic_sds_remote_device_general_frame_handler
         },
         [SCI_BASE_REMOTE_DEVICE_STATE_RESETTING] = {
-                .start_task_handler     = scic_sds_remote_device_default_start_request_handler,
                 .complete_task_handler  = scic_sds_remote_device_resetting_state_complete_request_handler,
                 .suspend_handler        = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler         = scic_sds_remote_device_default_resume_handler,
@@ -1266,7 +1211,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_
                 .frame_handler          = scic_sds_remote_device_general_frame_handler
         },
         [SCI_BASE_REMOTE_DEVICE_STATE_FINAL] = {
-                .start_task_handler     = scic_sds_remote_device_default_start_request_handler,
                 .complete_task_handler  = scic_sds_remote_device_default_complete_request_handler,
                 .suspend_handler        = scic_sds_remote_device_default_suspend_handler,
                 .resume_handler         = scic_sds_remote_device_default_resume_handler,
diff --git a/drivers/scsi/isci/remote_device.h b/drivers/scsi/isci/remote_device.h
index 04a2b54a0dd5..fb2b0079fe75 100644
--- a/drivers/scsi/isci/remote_device.h
+++ b/drivers/scsi/isci/remote_device.h
@@ -387,12 +387,6 @@ typedef void (*scic_sds_remote_device_ready_not_ready_handler_t)(
  */
 struct scic_sds_remote_device_state_handler {
         /**
-         * The start_task_handler specifies the method invoked when a user
-         * attempts to start a task management request for a remote device.
-         */
-        scic_sds_remote_device_request_handler_t start_task_handler;
-
-        /**
          * The complete_task_handler specifies the method invoked when a user
          * attempts to complete a task management request for a remote device.
          */